Metals carry heat

Look at the pans and kadhais in your kitchen. The ones that go on the fire are made of metal. Why?

Activity 4.3 (with an adult): put a metal spoon and a wooden spoon of about the same size into a glass of hot water at the same time. Wait a few minutes, then carefully touch the top end of each.

The metal spoon is hot at the top. The wooden spoon is hardly warm. Both were in the same water for the same time, so the heat must have travelled up through the metal, while the wood let very little through.

Heat moving from one part of a material to another is called conduction, and materials that pass heat along are conductors. Metals are good conductors of heat. Wood is a poor conductor of heat.

You have probably felt this. You cook Maggi in a small steel pan, then grab the pan without a cloth, and burn your fingers. The noodles were inside, but the metal carried the heat to your hand. That is why pans are metal, so heat reaches the food, and their handles are wood or plastic, so you can hold them.